CN1174686C - Equipment for handling cellulosic materials - Google Patents

Abstract

A process and screw in barrel apparatus(10)for expanding cellulosic materials is described. The expanded cellulosic material is useful as an animal feed and a nutrient source for fermentation processes.

Description

Equipment for handling cellulosic materials

technical field

The present invention relates to the treatment of cellulosic materials using an apparatus with a screw inside a sleeve to expand the materials so that they can be more advantageously used, for example, as animal feed and in fermentation processes. In particular, the present invention relates to a screw-in-sleeve apparatus capable of continuously treating cellulosic material using liquid ammonia capable of expanding the cellulosic material as it changes from a liquid to a gas as it exits the apparatus .

Background technique

The use of pressurized ammonia to increase protein availability and cellulose digestibility of cellulose-containing plant material (alfalfa) is described in US Patent No. 4,356,196 to Hultquist . Ammonia is provided in liquid form in a container, which saturates the plant material, and when the pressure within the container is rapidly reduced, it is volatilized and released in a flash. The resulting processed material is used for ethanol production or as feed for food or dairy animals. Dale in U.S. Patents US4600590 and US5037663 describes the use of various volatile chemicals to treat cellulose-containing materials, especially with ammonia, which is known as the AFEX process (Ammonia Freeze or Ammonia Fiber Explosion) . It handles pressure slightly higher than in the Hultquist . Holzapple et al. described an improved AFEX process in US Pat. No. 5,171,592, in which the treated biological product was post-treated with a superheated expansion agent vapor to remove residual expansion agent for recycling. The apparatus 20 has a mixing and stage valve 21 which is opened periodically. US Patent No. 4,644,060 to Chou is generally directed to the release of polysaccharides using supercritical ammonia. These patented methods are basically done in batches.

Other prior art related to AFEX process has European Patent EP77287; Dale, B.E., et al., "Biotechnology and Bioengineering Proceedings", No.12, 31-439 (1982); Dale, B.E., et al., "Industrial Microbiology "Proceedings of the Society for Industrial Microbiology", Vol.26(1985); Holtzapple, M.T. et al., "Applied Biochemistry and Biotechnology", VOL.28/29, 59-74(1991); Blasig, J.D. et al. , Resources, Energy Conservation and Recycling, 7:95-114 (1992); and Moniruzzaman, M. et al., Applied Biochemistry and Biotechnology, 67:113-126 (1997). These methods are all discrete.

Contents of the invention

It is therefore an object of the present invention to provide an improved apparatus for producing an expanded cellulosic material using an expanding agent. These and other objects will become more apparent by reference to the following description and accompanying drawings.

According to one aspect of the present invention there is provided an apparatus for producing an explosively expanding lignocellulosic material comprising:

(a) at least one rotatable screw mounted at opposite ends within a sleeve of an extruder, a feed inlet for lignocellulosic material through the sleeve to the screw, and output from the screw and sleeve a feed outlet, and heating and cooling means between the ends of the sleeve;

(b) a delivery tank containing pressurized liquid ammonia;

(c) a delivery line with a pump leading from the delivery box to a liquid inlet in the sleeve in a mixing zone containing kneading blocks on the downstream side of the feed inlet to mix the ammonia with the lignocellulosic material and to prevent The liquid ammonia flows to the feed inlet, and the delivery line contains a one-way valve after the pump, which is set to open at the pressure at which the liquid ammonia is being delivered to the liquid inlet, and to close above the vapor pressure of the liquid ammonia ;and

Wherein a liquid inlet through the sleeve to the screw is in the middle of the end to deliver liquid ammonia from the delivery tank whereby liquid ammonia is delivered to the screw under pressure and is kept under pressure inside the sleeve as liquefied ammonia , so that when the lignocellulosic material is discharged from the sleeve through an opening on a mold device at the feed outlet by the rotation of the screw, the cellulosic material containing liquid ammonia is explosively expanded by the change from liquid to gas, and in the mold device There is at least one heating element adapted to heat the mold assembly to cause explosive expansion of the liquid ammonia as it is expelled from the mold assembly, wherein the extruder, the opening in the mold assembly and the The heating elements cooperate with each other so that the expanded lignocellulosic material has an increase in the total available sugar content relative to the lignocellulosic material before being introduced into the feed inlet, and wherein adjacent to the A threaded member of the mold means tapers inwardly towards a longitudinal axis of the screw to force the lignocellulosic material with liquid ammonia out of the mold means.

According to another aspect of the present invention, there is provided a system for explosively expanding a lignocellulosic material using liquid ammonia comprising:

(a) An apparatus with at least one rotatable screw mounted at opposite ends within a sleeve of an extruder, a feed for lignocellulose passing through the sleeve to the screw at the upstream end Inlet, and output from the screw and sleeve, a feed outlet for lignocellulose, wherein a threaded member of the screw adjacent the feed outlet tapers inwardly towards a longitudinal axis of the screw, and wherein the threaded member has flight helicoids , and one of the flights adjacent to the feed outlet provides the tapered end, and the heating and cooling means between the ends of the sleeve for liquid ammonia passing through the sleeve in the middle of the end to the screw. Liquid inlet, whereby liquid under pressure is delivered to the screw through the liquid inlet, and is kept under pressure in the sleeve as liquid ammonia, whereby the lignocellulosic material passes from the sleeve through a heated mold assembly by rotation of the screw. Explosive expansion of a lignocellulosic material containing liquid ammonia by a liquid-to-gas change when the opening exits at a feed outlet, at least one heating element in the mold assembly, said heating element heating the mold assembly to cause the liquid to expand explosively;

(b) a liquid delivery tank containing liquid ammonia under pressure and connected to the inlet of the liquid inlet;

(c) a delivery line with a pump leading from the delivery box to a liquid inlet in the sleeve downstream of the feed inlet in a mixing zone comprising kneading blocks to mix the ammonia with the lignocellulosic material, and To prevent the flow of liquid ammonia to the feed inlet, the transfer line contains a check valve after the pump which is set to open at the pressure at which the liquid ammonia is being delivered to the liquid inlet and above the vapor pressure of the liquid ammonia closure;

(d) a defined space in which the system is located, isolated from the operator of the equipment, and continuously cleaned of ammonia released from the explosively expanded lignocellulosic material; and

(e) gas venting means spaced apart by a limited space adjacent to the die means to vent ammonia released from liquid ammonia and lignocellulosic material to the outside of the die means when the lignocellulosic material expands explosively, wherein the extruder, The heating of the openings in the mold means and the heating element cooperates so that, with respect to the lignocellulosic material being delivered to the feed inlet, the explosively expanded lignocellulosic material due to the explosive expansion of the liquid ammonia into a gas There is an increase in total available sugar content.

According to yet another aspect of the present invention there is provided an apparatus for continuously explosively expanding a lignocellulosic material comprising:

(a) at least one rotatable screw mounted with opposite ends in a sleeve of an extruder, having an inlet and heating and cooling means between the ends of the sleeve, and a feed outlet, and where the screw is tapered in profile at the outlet end with humped flight parts, and the screw also includes forward delivery flights on the upstream and downstream sides of the kneading block element, which provide a mixing zone between the screw ends ;

(b) means for supplying a lignocellulosic material to the inlet;

(c) a fluid inlet between the ends of the sleeve that provides liquid ammonia to the lignocellulosic material in the mixing zone at a pressure below the vapor pressure of the liquid ammonia, wherein the mixing zone combines the liquid ammonia with the lignocellulose Mix and prevent liquid ammonia from flowing into the feed inlet;

(d) a heated mold unit located at the feed outlet, with a heating element within the mold unit, wherein the outlet to the mold unit defines an opening that is 60% of the area of the opening at the inlet to the mold unit;

Where the shape of the extruder, the mixing zone, the opening in the die assembly, the heating elements in the die assembly, and the shape of the screw at the outlet end cooperate to provide sufficient pressure to maintain the liquid ammonia as a liquid so that the When the mixture of lignocellulosic material and liquid ammonia is extruded through the extruder, the liquid ammonia is converted into a gas, which causes the lignocellulosic material to expand explosively, thereby relative to the lignocellulosic material before being introduced into the feed inlet. Vegetable material, increasing the total available sugar content of the lignocellulosic material.

Description of drawings

Figure 1 is a schematic diagram representing a screw device 10 for the method;

FIG. 2 is a side view of a unitary threaded element 100 showing a single thread 106;

3 is an end view of two (2) threaded elements 100 and 101 partially interacting along parallel twin axes 21;

4 and 5 are end view sectional views of kneading blocks 200 and 201 in respective positions relative to each other, and they act in parallel along portions of the biaxial shaft 21;

6A to 6I are end-view cross-sectional views of the kneading blocks 200 and 201 of FIGS. 4 and 5 at respective relative positions;

7 and 8 show a sectional view and an end view of a single kneading block 200;

Figure 9 is an end view of a camel screw 102 adjacent to an extrusion die 18 extending from the apparatus and forcing cellulosic material into die block 18 and through die 18A;

Figure 10 is a side view of the hump screw 102 of Figure 9, also showing a plunger 103 and screw 104 for holding the screw 102 on a rod 105 (which serves as the shaft 21 of Figure 1), Wherein the rod 105 supports the screw members 100, 101 and the kneading blocks 200 and 201 along the screw rod 17.

Fig. 11 is a side view of an extruding screw showing various screw parts 100, 101 and kneading blocks 200, 201 in areas 1-7, wherein these areas will be shown in the following table 1;

Fig. 12 is a side view of a heating and cooling block installed along the longitudinal axis of the extrusion equipment 10, where x is the water outlet, ○ is the water inlet, and + is an electric heating cylinder installed in an opening of the sleeve 16 . Table 2 shows the dimensions of each position;

Figure 13 is a side view of the mold block 18;

Figure 14 is a top sectional view of mold 18A;

Figure 15 is a side sectional view of mold 18A;

Figure 16 is a view of the outlet of the mold 18A;

Figure 17 is a graph showing the total sugar concentration as a function of time after enzymatic hydrolysis of a cereal feed treated and not treated with the method and apparatus of the present invention. No mold 18A or mold block 18 was used. Extrusion device 10 can effectively increase the overall sugar concentration;

Figure 18 is a graph showing glucose as a specific sugar processed in the same manner as in Figure 17;

Figure 19 is a graph showing total sugar concentration as a function of time for cereal feed treated under various conditions by the method and apparatus of the present invention;

Figure 20 is a graph showing glucose as a particular sugar processed in the same manner as in Figure 19;

Figure 21 is a graph showing the total sugar concentration as a function of time for cereal feed treated under various conditions by the method and apparatus of the present invention;

Figure 22 is a graph showing the concentration of glucose as a specific sugar processed in the same manner as in Figure 21;

Figure 23 is a graph showing the in vivo digestibility of dry matter in a grain feed in the rumen of a cow as a function of time for various samples;

Figure 24 is a graph representing the dissolved concentration of NDF (Neutral Detergent Fiber neutral detergent fiber) of the sample of Figure 23 relative to time;

Figure 25 is a graph showing hemicellulose concentration versus time for the samples of Figure 23;

Figure 26 is a graph showing cellulose concentration versus time for the samples of Figure 23;

Figure 27 is a graph showing lignin concentration versus time for the samples of Figure 23;

Figure 28 is a graph showing ash content versus time for the samples of Figure 23;

FIG. 29 is a graph showing the digestibility of the samples of FIG. 23 as a function of time.

Detailed ways

The main purpose of the present invention is to use a screw and barrel apparatus 10 (shown in FIG. 1 ) to improve the ammonia fiber expansion (AFEX) process, which was previously only possible in a batch process reactor. The effectiveness of the treatment with the extrusion device 10 is limited to the increase in the enzymes or the digestibility of the rumen itself.

Example 1

The first step is to establish a safe ammonia operating environment. To do so, contact the Office of Radiation, Chemical, and Biological Safety (ORCBS) at Michigan State University (MSU), East Lansing, Michigan. According to their recommendation, a vinyl strip was wrapped completely around the area around the extrusion apparatus 10 which enclosed the auxiliary ventilation in the chamber to contain any ammonia leakage. The enclosure was tested with a smoke bomb producing 10,000 cubic feet of smoke per minute, no escape of smoke was observed. In addition, a horizontal fume hood 11 is connected to a ventilation duct to condense the ventilation volume immediately around the extruder delivery port 12 and outlet port 12 and the ammonia injection port 14 . Finally, two full-face respirators with detachable ammonia cartridges were purchased for use during all tests. A safety protocol was established and reviewed by everyone in any trial.

Extrusion apparatus 10 is a Baker-perkins MPC/V-30 (Saginaw, Mich.) type with side-by-side parallel twin screws 17, each screw consisting of threads 100, 101, 102 and kneading blocks 200, 201 (Figs. 2-10) form. The motor 15 delivers 3HP at 500RPM. The sleeve 16 has an outline diameter of 30 mm and a length-to-diameter ratio (L/D) of 10:1. The two (2) screws 17 rotate cooperatively and have a variable shape themselves. FIG. 11 shows the position of the segments 100 , 101 , 103 and the kneading blocks 200 , 201 . Table 1 shows the location of the components.

Table 1 area element length 1 Front conveyor screw 313/16 inches 2 1 kneading block 1/4 inch 3 Front conveyor screw 1 3/4 inches 4 Mixing area 5 kneading blocks, 1/4" each, 5 total, aligned at 45° 1 1/4 inches 5 forward feed screw 6 1/2 inches 6 kneading block 1/8 inch 7 Improved hump discharge screw 3 1/2 inches

The extrusion apparatus 10 is provided with control means (not shown) for both heating and cooling. Heating is carried out by electric cartridges in three zones (+ in FIG. 12 ) along the sleeve 16 and mold block 18 . Cooling is provided along the length of the sleeve 16 by cooling water delivered through the core of the sleeve section (⁠ and ∘ in FIG. 12 ). Dimensions are shown in Table 2.

The sleeve 16 and mold block 18 are heated to between 30°C and 100°C along their length. Preferably, the mold block 18 is heated to within this range.

Table 2 Inlet location 1 1/8" below centerline Spout location 1 1/8" below centerline Heater location 1 1/2 inches below centerline 2 3/4 inches 1/2 inch 4 11/16 inches 5 3/8 inches 3 3/4 inches 6 7/16 inches 10 7/8 inches 8 13/16 inches 8 5/16 inches 12 15/16 inches 11 3/4 inches 9 5/16 inches 11 5/16 inches 13 15/16 inches 14 5/8 inches

The mold 18A is cooled with air, wherein the processed feed is discharged through the mold 18A. The mold block 18 is provided with a heater (+ in Fig. 13). All interior surfaces of extrusion 10 were impregnated with a 63 µ-inch nitride and polished to provide excellent corrosion resistance. Screw parts 100, 101, 102 and kneading blocks 200, 201 (Figs. 2, 3, 4, 5 and 6A-6I) are made of heat-treated alloy steel.

The corrosion resistance of the individual threaded members 100, 101 was determined prior to any testing and no corrosion was observed during the testing.

A reciprocating diaphragm metering pump 50 for ammonia delivery was a Lewa, USA (Holliston, MA). The head of the pump 50 is fabricated from 316 stainless steel with Teflon seals. Pump 50 is capable of producing a metering range of 0.23 to 23.0 GPH (gallons per hour). The drive source supplies power of 3HP. The pump 50 is calibrated with water and the necessary conversions are made to determine the amount of liquid ammonia delivered using a particular stroke length and speed setting.

All conduits, fittings and valves used are fabricated from 316 stainless steel. The conduit used was 3/8 inch outside diameter, 0.065 inch wall thickness, rated at 6500 psig (pounds per square inch) gauge. All joints are rated for catheter pulse pressure. The pressure rating of the materials used is well within the safe range. This is done for safety when handling ammonia. Most connections adopt Swagelok fittings, but a few use NPT (National Standard Taper Pipe Thread), with a check valve 51 and bypass valves 52 and 53 . An ammonia tank 54 with a shut-off valve 55 is the delivery source for ammonia. A pressure relief valve 56 is used to purge the system of ammonia. A needle valve 57 is used to feed ammonia into the extrusion apparatus 10.

The organisms are conveyed into the extrusion device 10 via the feed pipe 20 . A feeder 19 leading to feed tube 20 is calibrated for a known period of time with the delivered material and the biomass is determined. Samples containing different amounts of moisture were calibrated separately.

The first material in this project is grain fodder or straw. Sample material is also referred to herein as organisms. This includes all above-ground parts of the corn plant except the grain and the corn itself.

Grain feed is obtained in a large square bale. The material is roughly chopped with a grinder mounted on a tractor. The material was then dried (less than 5% moisture) and further ground to pass through a 2mm screen on a rotary knife grinder. This dimension is between about 0.01 inch and 1 inch. Material is stored in plastic bags on the inside of cardboard drums. 10% to 80% water by weight is added. Fresh material can be used (typically at about 80% moisture, depending on dry matter weight).

As a result, the previously unmodified extrusion equipment used to process polymers required major modifications. As such, several modifications are required. First, a port 14 is machined to allow the ammonia to be injected. Port 14 is located approximately halfway down the length of sleeve 16 . Port 14 is chosen to minimize the equilibration time of the organisms with the ammonia. Equilibration time is approximately one (1) minute, but depends on delivery speed, amount of ammonia (ammonia loading), mold temperature, etc. Injection port 14 is fitted with a Teflon seal to minimize ammonia loss through port 14.

Second, the shape of the screw 17 is greatly modified to try to minimize the loss of ammonia through the feed tube 20 . Additionally, at the discharge end of the screw 17 there are two (2) humped screws 102 (one each shown in FIGS. 9 and 10 ). These threads were originally flat at the ends. The original design plugged the die block 18 just right. By making the end of each screw 103 a more tapered shape, organisms are introduced into die block 18 and expelled through die 18A without clogging.

The ammonia used was supplied in a 50 lb cylinder 54 provided with a liquid line to ensure liquid delivery. Pump 50 allows for controlled and precise delivery of ammonia. A check valve 51 is installed a little ahead of the injection port 14 to maintain the ammonia pressure in the conduit after the pump and help ensure liquid delivery. As soon as the pressure generated by the pump 50 reaches the opening pressure of the non-return valve 51 , the ammonia flows directly into the extrusion device 10 . The resealing pressure is set above the evaporation pressure of ammonia to prevent any leakage of ammonia through the check valve 51 . Bypass valves 52 and 53 are provided to allow the conduits to be drained after use of the extrusion apparatus with a pressure relief valve 56 for cleaning of the apparatus.

Once it was confirmed that the ammonia and biomass would flow together through the extrusion apparatus 10, an increasingly restrictive die 18 was used. First the mold block 18 is not used. However, since greater reliability can be obtained, block 18 and die 18A are added. A few fluffy bursts of cellulose were obtained with just block 18, but the enzymatic digestibility of the sample was only slightly higher than that of the treated sample. Additionally, the increased pressure created by a smaller mouth die 18A provides a more efficient process.

Much work has been done on the design of extrusion die 18A. However, biomixtures cannot be extruded through a standard die like any polymer or food product. Several rudimentary molds were tried, with little success. These molds are machined by hand and the rough edges and inner surfaces create the problem that the flow of organisms is hindered. Die 18A, which proved to be most useful, was machined with a 5° end mill to produce a smooth entry with a 40% taper to the entry area (ie, the exit was 60% of the entry area). With this mold block 18, fluffy bursts can be consistently achieved. This mold 18A is shown in FIGS. 13 , 14 and 15 . Its dimensions are as follows:

Extrusion die 18A

The larger port is the inlet and faces the extruder.

The area of the larger hole = π(0.5/2) ² + (1-0.5)0.5

= 0.446 inches ²

Area of the smaller hole = (0.25-y)[π(0.25-y)+1]

x=y/tan5°

Area of the smaller mouth = 0.268 ^inches2

Fluffy bursts are usually made at regular intervals. Some tests have shown a reproducibility of ±15 seconds. Steady state operation is either continuous or periodic depending on the ammonia loading and temperature. A higher amount of ammonia (ammonia/biomass > 1.5) promotes a slow discharge of the material from the extrusion apparatus 10 for a few minutes and then a burst from the die 18A. The ammonia loading is given as a mass ratio. For example, an ammonia amount of 3 means 3 pounds (or kilograms or grams, etc.) of ammonia relative to 1 pound (or kilograms, or grams, etc.) of dry biomass. Hereafter, ammonia amounts are given in M/M units, implying mass ratios. Observe that the pressure is about 300 psig and the torque is close to 50% until the fluff breaks out, at which point the pressure drops to Opsig and about 11% torque (usually no load value). Alternatively, small amounts of ammonia (<1.5M/M) indicate successive small bursts of fluff, which is the preferred mode of operation.

Other improvements have also been made. For example, Teflon layers are used to minimize pressure loss in the extruder. It was observed several times that the two metal-metal interfaces (the interface between the extrusion apparatus 10 and the die block 18 and the interface between the die block 18 and the die 18A) allow a part of the high pressure to escape, due to the formation of foam at the interface, so This escape is obvious. But a Teflon layer (not shown) is cut to fit around the mouth of the seal and then inserted between the two surfaces. After installing these seals, foam was no longer observed.

The main parameters that were changed were the temperature and the amount of ammonia. The water content of organisms is also altered, but with little success. A water content above 60% results in water being squeezed out of the biomass and flowing back into the biomass feed port. The degree of water content of the organisms is given as a percentage of the total (60% water content is 60 grams of water in 100 grams of the mixture of organisms and water). This creates problems in feeding the organisms into the extrusion device 10 because of the foam generated in the feed tube 20 by the ammonia. Alternatively, moisture levels below 60% do not effectively balance the ammonia, and thus do not achieve a fluffy burst. Therefore, all tests referred to in the Results section were obtained at a moisture content of 60%.

In regions 1-3 of Figure 11 the temperature varies in several ways. Generally, the first zone 1 in the middle of the biofeedhole is unheated and closed for cooling. In this context, heating means heating above room temperature. The cooling capacity of the first zone is removed because it condenses around the feed port, which would cause a blockage of the feed. The second zone 2 at the ammonia injection port 14 is slightly heated, depending on the set temperature of the mold block 18 . Too high a heating will vaporize the ammonia and result in a less effective treatment. The third zone 3 is typically heated to a temperature close to the average setpoint of the second zone and mold block 18 (FIG. 13). The temperature of the mold block 18 is considered the reaction temperature. Clearly there is an upper limit to the temperature of the mold block 18, as the fluffy explosion cannot be obtained above a set point of 70°C. This may be partly due to the partial evaporation of the ammonia in the third heating zone 3 . The mold temperature causes the temperature in the third region 3 to rise by heat conduction. This results in increased ammonia evaporation and less effective treatment. Additionally, ammonia may be squeezed out through the biofeed tube 20 due to a higher die block 18 temperature. Because the ammonia is not trapped as effectively as desired, the vapors leave the extrusion apparatus 10 freely. The lower temperature process will not generate such a high pressure on the feed tube 20 and thus will not suffer from this effect.

The amount of ammonia is another major parameter to change. Ammonia amount changed from 0.5 to 2.0. The calculated amount of ammonia is only an estimate of the actual amount treated. The extrusion apparatus 10 used had a relatively small L/D (10:1, D=30 mm), the measured length of the sleeve 16 was about 15.25 inches, and the only port 14 for ammonia injection was about 15.25 inches in the sleeve. Approximately halfway up the barrel 16. This creates certain problems because the ammonia flows back through the biofeed tube 20 .

Efforts have been made to create a high mixing zone prior to the ammonia injection port 14 by changing the profile of the screw 17 to effectively provide a plug that restricts the flow of ammonia back into the feed tube 20. The screw parts 100, 101, 102 and the kneading blocks 200, 201 are set in Table 2. The three first threads 100, 101, 102 are permanently bonded to the screw shaft by heating and cooling stress. These first sections dominate the forward feed screws, which typically run at 50% capacity and do not provide an effective restriction. Therefore, with the limited number of screw shafts available to implement the mixing zone, only five (5) mixing blades can be used.

There are other restrictions on mixing regions. The kneading blocks 200, 201 are aligned on a single rod 105 at various angles. When the kneading blocks 200, 201 are aligned at an angle of 0° to 90°, as shown in FIGS. One direction increases as it approaches 45° and decreases as the angle deviates from 45°. The angle is determined by looking down at the rod 105 , ie looking into the feed tube 20 , from the discharge end 15 . The angle given is the angle of the outermost kneading block 201 relative to the next kneading block 200 below the shaft 21 . For example, kneading blocks 200 and 201 are aligned at 30°, with one blade on the shaft and the next rotated 30° clockwise relative to the former. At 0° there is no mixing and at 90° there is maximum mixing. Kneading blocks 200 and 201 aligned at a negative angle invert and force flow in the opposite direction.

The table below shows the transferability of the kneading blocks 200 and 201, where F is forward and R is reverse.

most Transmission the smallest

45°F 60°F 90° 60°R 45°R

Several mixed zone alignments were tried, but most of them had limitations on torque. In other words, only a small amount of bioenergy is sent through the machine before the torque approaches its maximum value. The torque limit depends on the rotational speed of the twin shaft 21 (supported by the rod 105). Therefore, a 45° mixing zone is implemented. This allows a good plug to form and also allows a great flow of organisms. Observation of the screws 100 and 101 after filling indicated that the mixing zone prior to port 14 was approximately 90% full, while the other sections outside of port 14 were approximately 50% filled. Unfortunately, the length of the mixing zone is not long enough to provide a significant confinement of ammonia vapor. Consequently, some of the injected ammonia is lost through the feed tube 20 due to evaporation. Therefore, the actual amount of ammonia used in the treatment is less certain, but all operations are classified according to the amount of ammonia injected.

Example 2

First, the primary measure to quantitatively determine the effectiveness of the method is enzymatic hydrolysis. Since the main purpose is to demonstrate the operation of the screw-and-sleeve technology used to deliver AFEX, the maximum sugar concentration is not the central point, but relative digestibility. Therefore, all samples were hydrolyzed in a citrate buffer at pH = 4.8 with an amount of 15 IU/g of cellulase and a beta-glucosidase amount of 1 mL/mL of cellulase. The cellulase used was CELLUCLAST and the beta-glucosidase used was NOVO 188, both produced by Novo Nordisk (Franklinton, NC). All samples were hydrolyzed with a 5% by weight solution in an agitated water bath for up to 48 hours at a temperature of 50°C. Major decompositions occurred for glucose, xylose, galactose, arabinose, and glycosides in a pilot HPLC column. Additional decompositions were performed in an acid column, which produced glucose and synthetic sugar peaks, including xylose, mannose, and galactose concentrates. Finally, a YSI (Yellow Springs, Ohio) instrument was also used and glucose concentrates were produced.

Using mold block 18 alone produced a fluffy explosion that resulted in a total sugar concentration (sum of glucose, xylose, galactose, arabinose, and glucoside) after 24 hours of enzymatic hydrolysis that was completely untreated 2.4 times that of the sample. The glucose concentration of this material was 2.1 times that of the completely untreated material after the same amount of time. The same material produced a total sugar concentration 2 times higher than that of organisms treated in a screw-and-sleeve device without ammonia, and a corresponding glucose concentration of 2.5 times that of organisms treated in a screw-and-sleeve device without ammonia. times. Further testing with mold block 18 alone (without mold 18A) yielded a total sugar concentration 3.5 times higher than the untreated material and 3.4 times higher than the untreated material after 24 hours of hydrolysis.

The best results obtained with Die 18A showed that a total sugar concentration was obtained which was 2.4 times higher than that of the completely untreated material after 6 hours of enzymatic hydrolysis. The glucose concentration at this point was 2.3 times higher than that obtained with this completely untreated material.

In general, the most effective treatments for enzymatic hydrolysis are at low temperatures. The higher the temperature of the mold block 18 used (above 70° C.), the less efficient the process will be. This may be due in part to more ammonia escaping the equipment at a higher temperature. However, with a lower temperature, the ammonia will remain in contact with the organisms for a longer period of time and obtain a more effective treatment. The test results are shown in Figures 19-22 and Table 3.

table 3 Treated substrates for field trials Sample temperature °C Ammonia humidity (water content) A-untreated 50 N/A 60% B unheated 1.0 60% C 55 1.5 60% D 65 0.8 60% E 65 1.0 60% F 65 1.5 60% G 65 1.6 60 %H 65 2.0 60% I 55 1.5 60%

Example 2

Following the enzymatic digestibility test, it is desirable to test the material for ruminant digestibility in the field. For this, several samples were generated with different temperature treatments and amounts of ammonia. They were brought to the Department of Animal Science at Texas A&M University (College Station, Texas) and analyzed for digestibility in situ. Samples were analyzed on a dry weight basis after weight loss over a known period of time. The material is placed in a small permeable pocket of known weight and dried to determine the amount of dry matter. The pocket is then placed in the rumen of a castrated cow with a tubular organ inserted. This is a castrated cow with a surgically inserted catheter to allow access to the animal's rumen. The digestibility of the material was determined as a percent weight loss of the material by removing the bags at specific intervals (0, 3, 6, 12, 24, 28 and 96 hours), thoroughly washing and drying. The weight loss of material within a particular pocket is known as dry matter digestibility, or DMD.

Conduct a field test. The tests focused on the screw-barrel process material and the control performed was to treat a sample at 50°C without ammonia.

The test results are shown in Figs. 23-29. The 48-hour digestibility tested is tabulated in Table 4. Tests showed that the digestibility of the extruded material at 48 hours was as high as 77.4% of the material was digestible, compared to only 63.0 in the screw-barrel process without process control (with ammonia) %. Typical rumen transit times are 48 hours or less.

Table 4-48 hours dry matter digestibility test

ID DMD NH3Load T(℃)

F 77.4 1.5 65

H 76.1 2.0 65

C 73.5 1.5 55

I 73.4 1.5 55

E 71.6 1.0 65

G 70.5 1.6 65

B 70.4 1.0 0

D 68.0 0.8 65

A 63.0 0.0 50

Note:

DMD is dry matter digestibility expressed as a percentage.

The amount of NH3 is the ratio of the amount of injected ammonia relative to the treated biomass.

T(°C) is the set temperature of the mold.

At 48 hours, the effect of temperature and amount of ammonia is not particularly clear. The two most effective treatments obtained were at a temperature of 65°C with ammonia levels of 1.5 and 2.0 (samples F and H, respectively). The digestibility of F (77.4%) was only slightly higher than that of H (76.1%). However, Sample G with 1.6 M/M ammonia and a temperature of 65°C was only the sixth most digestible material with a digestibility of 70.5%. The third and fourth most effective treatments (Samples C and I respectively) were identical samples and showed excellent agreement, differing by only 0.05% points and having an average digestibility of 73.5%. Samples I and C were produced at an ammonia level of 1.5M/M at a temperature of 55°C. In the test, samples H and F were consistently the most digestible, while sample H was the most digestible at all time points except 48 hours and 96 hours.

The composition of each material at each time point was also determined. Assays were used to determine the amount of neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin and insoluble ash. The NDF assay gives the amount of cellulose, hemicellulose, lignin and ash in a sample. ADF treatment removes hemicellulose, lignin treatment removes cellulose, and ash treatment removes lignin.

Both cellulose and hemicellulose are considered digestible to some extent, while lignin is considered indigestible. Therefore, a significant reduction in the lignin content is desired and has been achieved. The results showed that the lignin content of the samples treated in the plant at 65°C was reduced by 20.9%, compared to an average reduction of only 11.9% for the treatment control in the plant without ammonia.

The speed at which digestion occurs is also important. In all cases, the initial digestion rates for all ammonia-treated samples were higher than for material treated in the facility without ammonia. In this case, the initial rate of digestion was determined to be a rate of digestion between 3 and 6 hours. In many cases, the samples gained weight from the 0-3 hour samples, which did not provide acceptable data. This could be explained by insufficient washing of the 3 hour sample, which could leave trapped dust, soluble particulates and microorganisms in the pockets. Another explanation is that the material used to fill the 0 hour pocket contained more dust than the 3 hour sample and would have allowed more material to be washed off. The maximum digestion rate was 2.25 times that of the experimental control (untreated control). The maximum observed velocity for sample H was 6.16%/hour.

The data also indicated that hemicellulose and cellulose particles were reduced over time, implying that digestion of these components occurred. The hemicellulose content of the first trial decreased until 12 hours, increased at 24 hours, then decreased again until the end of the test. Cellulose microparticles increased until 12 hours and then decreased. This suggests that hemicellulose is digested first until the cellulose is efficiently broken down, and then hemicellulose is digested. As expected, the concentration of non-digestible lignin rose steadily as the experiment progressed.

In Examples 1 and 2, a screw-and-sleeve apparatus 10 was used to facilitate the AFEX process. Enzymatic digestibility of the cereal feed increased overall sugar production by 250%, and field ruminant digestibility increased by 32% (from 53.8% to 71.2%) for the completely untreated sample. Additionally, the total sugar yield for enzymatic digestibility of cereal feed increased by 240%, and on-site ruminative digestibility increased by 19% (from 63.0% to 77.4%). The screw-and-sleeve method also produced results that compared well with the batch method, leading to the conclusion that such a method could be as effective as the proven batch method.

Other results of the trial were also encouraging. Significant reductions in lignin were desired and achieved, with an average reduction of 11.9% (from 8.42% to 6.66%, with a maximum reduction of 20.9%). A high rate of digestion was also observed. The highest digestion rate was 2.3 times that of the control used in each experiment. Preferably, a higher degree of reduction in cellulose and hemicellulose was observed during the test, implying utilization of these components.

The system of the present invention can be used to recover the gas exhausted from the shroud 11 . Use conventional gas (ammonia) reception. This aspect of the invention is well known to those skilled in the art.

Various types of devices can be used to implement the present invention. Plastic extruders can be modified to practice the invention, and pulp defibrators can also be modified to carry out the method of the invention wherein the screw is in close spaced contact with a sleeve. All such modifications will be apparent to those skilled in the art.

The foregoing description is only intended to be exemplary for explaining the invention, which is limited only by the appended claims.

Claims (7)

1. An apparatus for producing an explosively expanding lignocellulosic material comprising: (a) at least one rotatable screw mounted at opposite ends within a sleeve of an extruder, a feed inlet for lignocellulosic material through the sleeve to the screw, and output from the screw and sleeve a feed outlet, and heating and cooling means between the ends of the sleeve; (b) a delivery tank containing pressurized liquid ammonia; (c) a delivery line with a pump leading from the delivery box to a liquid inlet in the sleeve in a mixing zone containing kneading blocks on the downstream side of the feed inlet to mix the ammonia with the lignocellulosic material and to prevent The liquid ammonia flows to the feed inlet, and the delivery line contains a one-way valve after the pump, which is set to open at the pressure at which the liquid ammonia is being delivered to the liquid inlet, and to close above the vapor pressure of the liquid ammonia ;and Wherein a liquid inlet through the sleeve to the screw is in the middle of the end to deliver liquid ammonia from the delivery tank whereby liquid ammonia is delivered to the screw under pressure and is kept under pressure inside the sleeve as liquefied ammonia , so that when the lignocellulosic material is discharged from the sleeve through an opening on a mold device at the feed outlet by the rotation of the screw, the cellulosic material containing liquid ammonia is explosively expanded by the change from liquid to gas, and in the mold device There is at least one heating element adapted to heat the mold assembly to cause explosive expansion of the liquid ammonia as it is expelled from the mold assembly, wherein the extruder, the opening in the mold assembly and the The heating elements cooperate so that the expanded lignocellulosic material has an increase in total available sugar content relative to the lignocellulosic material before being introduced into the feed inlet, and wherein adjacent to the A threaded member of the mold means tapers inwardly towards a longitudinal axis of the screw to force the lignocellulosic material with liquid ammonia out of the mold means. 2. Apparatus as claimed in claim 1, characterized in that the mold means has an opening which tapers inwardly so that the cellulosic material is compressed by the mold before being expelled. 3. Apparatus as claimed in claim 1 or 2, characterized in that the sleeve is provided with spaced apart heating and cooling elements arranged along its length as heating and cooling means for maintaining the lignocellulosic material at a certain A temperature which favors the expansion of the cellulosic material as it exits the mold device. 4. A system for explosively expanding a lignocellulosic material using liquid ammonia comprising: (a) An apparatus with at least one rotatable screw mounted at opposite ends within a sleeve of an extruder, a feed for lignocellulose passing through the sleeve to the screw at the upstream end Inlet, and output from the screw and sleeve, a feed outlet for lignocellulose, wherein a threaded member of the screw adjacent the feed outlet tapers inwardly towards a longitudinal axis of the screw, and wherein the threaded member has flight helicoids , and one of the flights adjacent to the feed outlet provides the tapered end, and the heating and cooling means between the ends of the sleeve for liquid ammonia passing through the sleeve in the middle of the end to the screw. Liquid inlet, whereby liquid under pressure is delivered to the screw through the liquid inlet, and is kept under pressure in the sleeve as liquid ammonia, whereby the lignocellulosic material passes from the sleeve through a heated mold assembly by rotation of the screw. Explosive expansion of a lignocellulosic material containing liquid ammonia by a liquid-to-gas change when the opening exits at a feed outlet, at least one heating element in the mold assembly, said heating element heating the mold assembly to cause the liquid to expand explosively; (b) a liquid delivery tank containing liquid ammonia under pressure and connected to the inlet of the liquid inlet; (c) a delivery line with a pump leading from the delivery box to a liquid inlet in the sleeve downstream of the feed inlet in a mixing zone comprising kneading blocks to mix the ammonia with the lignocellulosic material, and To prevent the flow of liquid ammonia to the feed inlet, the transfer line contains a check valve after the pump which is set to open at the pressure at which the liquid ammonia is being delivered to the liquid inlet and above the vapor pressure of the liquid ammonia closure; (d) a defined space in which the system is located, isolated from the operator of the equipment, and continuously cleaned of ammonia released from the explosively expanded lignocellulosic material; and (e) gas venting means spaced apart by a limited space adjacent to the die means to vent ammonia released from liquid ammonia and lignocellulosic material to the outside of the die means when the lignocellulosic material expands explosively, wherein the extruder, The heating of the openings in the mold means and the heating element cooperates so that, with respect to the lignocellulosic material being delivered to the feed inlet, the explosively expanded lignocellulosic material due to the explosive expansion of the liquid ammonia into a gas There is an increase in total available sugar content. 5. The system of claim 4, wherein the mold means has an opening which tapers inwardly so that the lignocellulosic material is compressed by the mold before being expelled from the mold means. 6. A system as claimed in claim 4 or 5, characterized in that the sleeve is provided with spaced apart heating and cooling elements arranged along its length as heating and cooling means for maintaining the lignocellulosic material at a certain A temperature which favors the expansion of the cellulosic material as it exits the mold device. 7. An apparatus for continuously explosively expanding a lignocellulosic material comprising: (a) at least one rotatable screw mounted with opposite ends in a sleeve of an extruder, having an inlet and heating and cooling means between the ends of the sleeve, and a feed outlet, and where the screw is tapered in profile at the outlet end with humped flight parts, and the screw also includes forward delivery flights on the upstream and downstream sides of the kneading block element, which provide a mixing zone between the screw ends ; (b) means for supplying a lignocellulosic material to the inlet; (c) a fluid inlet between the ends of the sleeve that provides liquid ammonia to the lignocellulosic material in the mixing zone at a pressure below the vapor pressure of the liquid ammonia, wherein the mixing zone combines the liquid ammonia with the lignocellulose Mix and prevent liquid ammonia from flowing into the feed inlet; (d) a heated mold unit located at the feed outlet, with a heating element within the mold unit, wherein the outlet to the mold unit defines an opening that is 60% of the area of the opening at the inlet to the mold unit; Where the shape of the extruder, the mixing zone, the opening in the die assembly, the heating elements in the die assembly, and the shape of the screw at the outlet end cooperate to provide sufficient pressure to maintain the liquid ammonia as a liquid so that the When the mixture of lignocellulosic material and liquid ammonia is extruded through the extruder, the liquid ammonia is converted into a gas, which causes the lignocellulosic material to expand explosively, thereby relative to the lignocellulosic material before being introduced into the feed inlet. Vegetable material, increasing the total available sugar content of the lignocellulosic material.

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